<template>
  <div class="upload-file">
    <el-upload ref="fileUpload" multiple :action="uploadFileUrl" :before-upload="handleBeforeUpload" :file-list="fileList" :limit="limit" :on-error="handleUploadError" :on-exceed="handleExceed" :on-success="handleUploadSuccess" :show-file-list="false" :headers="headers" class="upload-file-uploader">
      <!-- 上传按钮 -->
      <el-button type="primary">选取文件</el-button>
    </el-upload>
    <!-- 上传提示 -->
    <div v-if="showTip" class="el-upload__tip">
      请上传
      <template v-if="fileSize">
        大小不超过 <b style="color: #f56c6c">{{ fileSize }}MB</b>
      </template>
      <template v-if="fileType">
        格式为 <b style="color: #f56c6c">{{ fileType.join("/") }}</b>
      </template>
      的文件
    </div>
    <!-- 文件列表 -->
    <transition-group class="upload-file-list el-upload-list el-upload-list--text" name="el-fade-in-linear" tag="ul">
      <li v-for="(file, index) in fileList" :key="file.uid" class="el-upload-list__item ele-upload-list__item-content">
        <el-link :href="`${baseUrl}${file.url}`" :underline="false" target="_blank">
          <span class="el-icon-document"> {{ getFileName(file.name) }} </span>
        </el-link>
        <div class="ele-upload-list__item-content-action">
          <el-link :underline="false" type="danger" @click="handleDelete(index)">删除</el-link>
        </div>
      </li>
    </transition-group>
  </div>
</template>

<script setup lang="ts">
  import { getToken } from "@/utils/auth";
  import { getCurrentInstance, ComponentInternalInstance, ref, computed, watch } from "vue";

  const props = defineProps({
    modelValue: [String, Object, Array] as any,
    // 数量限制
    limit: {
      type: Number,
      default: 5
    },
    // 大小限制(MB)
    fileSize: {
      type: Number,
      default: 5
    },
    // 文件类型, 例如['png', 'jpg', 'jpeg']
    fileType: {
      type: Array as () => Array<any>,
      default: () => ["doc", "xls", "ppt", "txt", "pdf"]
    },
    // 是否显示提示
    isShowTip: {
      type: Boolean,
      default: true
    }
  });

  const { proxy } = getCurrentInstance() as ComponentInternalInstance;
  const emit = defineEmits(["update:modelValue"]);
  const number = ref(0);
  const uploadList = ref<any[]>([]);
  const baseUrl = import.meta.env.VITE_APP_BASE_API;
  const uploadFileUrl = ref(import.meta.env.VITE_APP_BASE_API + "/common/upload"); // 上传文件服务器地址
  const headers = ref({ Authorization: "Bearer " + getToken() });
  const fileList = ref<any[]>([]);
  const showTip = computed(() => props.isShowTip && (props.fileType || props.fileSize));

  watch(
    () => props.modelValue,
    (val) => {
      if (val) {
        let temp = 1;
        // 首先将值转为数组
        const list = Array.isArray(val) ? val : props.modelValue!.split(",");
        // 然后将数组转为对象数组
        fileList.value = list.map((item: any) => {
          if (typeof item === "string") {
            item = { name: item, url: item };
          }
          item.uid = item.uid || new Date().getTime() + temp++;
          return item;
        });
      } else {
        fileList.value = [];
        return [];
      }
    },
    { deep: true, immediate: true }
  );

  // 上传前校检格式和大小
  function handleBeforeUpload(file: any) {
    // 校检文件类型
    if (props.fileType.length) {
      const fileName = file.name.split(".");
      const fileExt = fileName[fileName.length - 1];
      const isTypeOk = props.fileType.indexOf(fileExt) >= 0;
      if (!isTypeOk) {
        proxy!.$modal.msgError(`文件格式不正确, 请上传${props.fileType.join("/")}格式文件!`);
        return false;
      }
    }
    // 校检文件大小
    if (props.fileSize) {
      const isLt = file.size / 1024 / 1024 < props.fileSize;
      if (!isLt) {
        proxy!.$modal.msgError(`上传文件大小不能超过 ${props.fileSize} MB!`);
        return false;
      }
    }
    proxy!.$modal.loading("正在上传文件，请稍候...");
    number.value++;
    return true;
  }

  // 文件个数超出
  function handleExceed() {
    proxy!.$modal.msgError(`上传文件数量不能超过 ${props.limit} 个!`);
  }

  // 上传失败
  function handleUploadError(err: any) {
    proxy!.$modal.msgError("上传文件失败");
  }

  // 上传成功回调
  function handleUploadSuccess(res: any, file: any) {
    if (res.code === 200) {
      uploadList.value.push({ name: res.fileName, url: res.fileName });
      uploadedSuccessfully();
    } else {
      number.value--;
      proxy!.$modal.closeLoading();
      proxy!.$modal.msgError(res.msg);
      (proxy!.$refs.fileUpload as any).handleRemove(file);
      uploadedSuccessfully();
    }
  }

  // 删除文件
  function handleDelete(index: any) {
    fileList.value.splice(index, 1);
    emit("update:modelValue", listToString(fileList.value));
  }

  // 上传结束处理
  function uploadedSuccessfully() {
    if (number.value > 0 && uploadList.value.length === number.value) {
      fileList.value = fileList.value.filter((f) => f.url !== undefined).concat(uploadList.value);
      uploadList.value = [];
      number.value = 0;
      emit("update:modelValue", listToString(fileList.value));
      proxy!.$modal.closeLoading();
    }
  }

  // 获取文件名称
  function getFileName(name: any) {
    if (name.lastIndexOf("/") > -1) {
      return name.slice(name.lastIndexOf("/") + 1);
    } else {
      return "";
    }
  }

  // 对象转成指定字符串分隔
  function listToString(list: any, separator?: any) {
    let strs = "";
    separator = separator || ",";
    for (let i in list) {
      if (list[i].url) {
        strs += list[i].url + separator;
      }
    }
    return strs !== "" ? strs.substr(0, strs.length - 1) : "";
  }
</script>

<style scoped lang="scss">
  .upload-file-uploader {
    margin-bottom: 5px;
  }

  .upload-file-list .el-upload-list__item {
    border: 1px solid #e4e7ed;
    line-height: 2;
    margin-bottom: 10px;
    position: relative;
  }

  .upload-file-list .ele-upload-list__item-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: inherit;
  }

  .ele-upload-list__item-content-action .el-link {
    margin-right: 10px;
  }
</style>
